Here's a helpful comparison for understanding why F. Scott Fitzgerald's short story The Curious Case of Benjamin Button really shouldn't have been made into a movie: Consider Franz Kafka's Metamorphosis, in which Gregor Samsa awakens one morning to find himself transformed into a "gigantic vermin." How would that transformation be portrayed? What would the "vermin" look like? What special effects would be required? Would the actor be inside some kind of suit, or just providing an off-screen voice?

All of those would be important questions for a filmmaker and they miss the point entirely. Metamorphosis like The Curious Case of Benjamin Button is an allegory that begins with a purely literary conceit. And as viewers start spending time on the "How did they do that?" element, they lose sight of what that purely literary conceit was supposed to convey.

Director David Fincher and screenwriter Eric Roth (Forrest Gump) nevertheless attempt to tell the story of Benjamin Button (Brad Pitt), who is born on Armistice Day in 1918. He's left on a doorstep by his father (Jason Flemyng) when his mother dies in childbirth, to be raised by a nurse (Taraji P. Henson) at an old-age home.

Benjamin's unique predicament? He is born an old man or, at least in the source material, he is born an old man. In the film, he's born a special-effects baby with a wrinkled old-man face and limbs. As Benjamin ages in reverse, Brad Pitt's heavily made-up face is superimposed over a succession of variously sized bodies. For the first 45 minutes, this is the focal point: an odd-looking digital amalgam of a wrinkled Pitt and a stunt torso.

Once Pitt is fully himself, the story settles into a more comfortable albeit expansive storytelling rhythm. Benjamin goes to work on a merchant ship with a high-spirited captain (Jared Harris); he has an affair with the married wife (Tilda Swinton) of an English diplomat in Russia; he re-connects with his "childhood" friend Daisy (Cate Blanchett).

Pitt has always proved somewhat elusive as a straight dramatic actor, and it's even tougher when he's playing a character who's such an enigma. But once Fincher and Roth home in on the romance between Benjamin and Daisy and the inevitability of their growing apart they find an emotional hook that keeps the focus as sharp as Claudio Miranda's rich cinematography.

But there's still the question of what, ultimately, this odd little tale is supposed to be about. While Benjamin Button's chronology spans decades, its ideas don't actually feel particularly sweeping. Roth distills it all down to stuff along the lines of "life is short and precious, and you should live it to the fullest while you have the chance." Simplistic though it is, the message does prove potent.

That's really the only explanation for why Benjamin Button finds itself an early Oscar favorite: People are responding to the fact that they can tell its heart is in the right place. Fincher and Roth don't particularly care if you think about life, so long as you feel life. Thinking might only get you in trouble like wondering why, if Benjamin as an 8-year-old has a 70-year-old face on an 8-year-old body, he actually shrinks to the size of a toddler while in his senior years. Mortality is too abstract a concept to worry about when there's a special-effects team to wrangle.